1. Field of the Invention
The invention relates to a method for manufacturing a polymer with triaromatic methane units as basic building blocks, the electric conductivity of which is obtained through the formation of charge transfer complexes.
2. Description of the Prior Art
Such polymers are suitable for the manufacture of housings and protective coatings of electrical equipment as well as for coatings covering elements for walls and furniture.
In electrotechnology there is a large demand for polymers, the electric conductivity of which can be chosen freely, within a range between 10.sup.-14 and 10.sup.-7 (ohm cm).sup.-1, referred to the cross section of the synthetic resin compound, in which the synthetic resin compound still acts as an insulator. This makes it possible to maintain a sufficient insulating effect and at the same time prevent electrostatic charging. These polymers can be used as antistatic surface coatings as well as for insulating between metallic sides with different potentials. In the latter case, the bulk conductivity is large enough to avoid electric breakdowns on the surface, which are caused by conductive contamination.
British Patent 10 67 260 discloses a synthetic polymer which is a nitrogen-containing polymer, in which the electric conductivity is achieved by the formation of charge-transfer complexes.
Furthermore, polymers are known, in which increased electron conductivity is achieved by admixing to its base material electron-conducting fillers such as copper, gold, platinum, carbon or graphite. Synthetic resins with these additives have the disadvantage that the conductivity is not increased if the content of these fillers is small, but that, if the addition is increased, the conductivity is increased suddenly so that it increases beyond the desired value and the insulation property gets lost.
Polymers without additives have an electric bulk conductivity from 10.sup.-15 to 10.sup.-18 (ohm cm).sup.-1. For these polymers to be used for the manufacture of housings and coatings of electrical equipment, they should have an electric bulk conductivity which is approximately between 10.sup.-17 and 10.sup.-14 (ohm cm).sup.-1.